Check the contractor’s BuildZoom score, which ranks California contractors based on license status, insurance, work history, and verified reviews. Look for BBB accreditation and manufacturer certifications like James Hardie Elite Preferred status. Ask for recent project references and verify they’re licensed, bonded, and insured. Avoid contractors who give vague estimates, require large upfront payments, or pressure you to sign immediately. Quality contractors give you detailed written estimates and warranty their workmanship.